The invention relates to paper manufacture, and particularly to the manufacture of paper from recycled furnish.
Recycled paper is particularly susceptible to the development of “waves” in the paper, which typically extend in the machine direction but sometimes also extend in the cross-machine direction. Desirably, the paper should lay flat without ridges or waves. The degree to which the paper deviates from this ideal flat condition can vary, and sometimes the deviation is great enough to cause the paper to be unsuitable for its intended use. Currently, however, there is no known commercially available device that is relatively inexpensive, that is simple to use, and that can measure and quantify the “waviness” of paper. Instead, the waviness typically is subjectively evaluated by a person touching and feeling a sample of the paper. Such subjective evaluation obviously is subject to problems with regard to accuracy, repeatability, and standardization.